On a sodden day in Bavaria, the Polish striker took exception to a challenge from the World Cup-winning defender, during an open training session at the club's Sabener Strasse training ground.

The German centre-back came sliding in to make a challenge on the former Borussia Dortmund striker, with the ball nowhere in sight.

The pair had to be separated by Bayern skipper Philipp Lahm and a number of other teammates, who sought to diffuse the tension.

However, as they pointed and shouted at one another, Bayern chief Pep Guardiola ordered the duo off the field and into the changing rooms.

Unhappy: Lewandowski took exception to a challenge from Boateng (Photo: Getty)

It is not the first time Boateng has been caught getting into a heated situation on the training ground, having made headlines while with former club Manchester City for a training ground scrap with Mario Balotelli.

Since winning the Bundesliga title, Guardiola's side have seen their season unravel.

They've lost five of their last six matches - with victory over Barcelona in the Champions League final also coming in vain - while they were also beaten on penalties by Borussia Dortmund in the German Cup.

Bayern face Mainz in their final game of the season on Saturday at the Allianz Arena.